public class Example02 {
    public static void main(String[] args) {
        student stu1 = new student();
        student stu2 = null;
        stu2 = stu1;
        stu1.name = "小明";
        stu1.age = 20;
        stu2.age = 50;
        stu1.read2();
        stu2.read2();
    }
}
